Depth cues

Question 1

Depth cues definition

Answer 1

visual cues that allow someone to perceive the world in three dimensions and judge the distance and position of objects in their environment

Question 2

Primary depth cues

Answer 2

• Come from our body
• Can be classified as a biological influence on our perception

Question 3

Secondary or pictorial depth cues

Answer 3

• Come from the image cast on our retina
• Are generated based on psychological influences on perception

Question 4

Binocular depth cues require

Answer 4

both eyes

Question 5

Monocular depth cues require

Answer 5

one eye

Question 6

Binocular depth cues definition

Answer 6

depth cues that rely on information from both eyes

Question 7

There are two binocular depth cues:
- both primary

Answer 7

1. Retinal disparity
2. Convergence

Question 8

Retinal disparity

Answer 8

• The difference (disparity) between the images on the retinas of each eye when viewing something.
• Each retina receives a slightly different image due to the different angles of view.
• The brain combines the two images to make one 3-D perception.
• Where the information has more difference the object must be closer to us, and where the information has less difference, the object must be further away from us

Question 9

Convergence

Answer 9

• As objects move closer to us, our eyes turn inwards to focus the light from the object onto our fovea (centre of the retina)
• The closer an object is to us, the more tension is placed on our orbital muscles (the muscles that control eye movement)
• the greater the tension on the orbital muscles, the further they are converging inwards
• The cortex processes the level of tension placed on our orbital muscles to help determine how far an object is from us
• the more tension the closer the object is to us, the less tension the further away the object is from us

Question 10

Monocular depth cues definition

Answer 10

cues to assist the perception of depth that only require information from one eye

Question 11

There are three monocular depth cues

Answer 11

• Accommodation (primary, biologically-based depth cue)
• Motion parallax
• Pictorial depth cues (psychological influences on depth perception)

Question 12

Accommodation

Answer 12

• The lens in our eyes changes shape to help focus the light from our world onto our retina
• It bulges to focus on objects that are close to us and flattens to focus on objects that are further away from us
• The cortex draws on information about the degree of tension placed on the ciliary muscles (which control the shape of the lens) and uses this information to help determine the distance of an object from the observer

Question 13

Motion parallax

Answer 13

• Motion parallax uses our perception of movement to help us gauge how far away things are.
• The less objects in our visual field move, the further they are away from us

Question 14

Pictorial depth cues definition

Answer 14

cues from the image we are looking at which indicate the distance of objects from an observer

Question 15

Pictorial depth cues - THRIL

Answer 15

• Texture Gradient
• Height in the Visual Field
• Relative Size
• Interposition
• Linear Perspective

Question 16

Linear perspective

Answer 16

Based on the apparent convergence of parallel lines as the lines recede into the distance
- lines going together gives us an indication of depth

Question 17

Interposition (overlap)

Answer 17

If one object partially obscures the retinal image of another object, then it must be closer to the observer
- the object that is obscured is actually further away because the one in front is blocking the perception of part of the object behind it

Question 18

Texture gradient

Answer 18

Objects can be seen in finer detail and with greater clarity when they are closer to the observer than when they are further away
- closer you can see more detail, further away seems like a blur

Question 19

Relative size

Answer 19

Objects cast a larger retinal image when they are closer to the observer than when they are further away
- as objects come closer to us they appear to be larger and when they move further away from us they appear to be smaller

Question 20

Height in visual field

Answer 20

Objects that are positioned closer to the horizon are perceived as being further away than objects that are closer to us
- As objects go into the distance they actually go closer to the horizon, so the further an object is from the observer, the closer it is to the horizon